It’s not exactly a refutation of the flat earth theory, but Dominican geography professor John Tandarich will find out sometime next spring whether or not a discovery he made in early 2006 overturns a long-held assumption about the formation of modern day Chicago area geography.
In the spring of 2006 Tandarich stood watching as workers pounded pilings into the earth around what was to be the site of the new Parmer Hall. Approximately 14 feet down, they hit ground water, which was no surprise to them or to Tandarich-it has long been surmised that the remnants of an underground river may flow through parts of Oak Park and River Forest.
What did surprise Tandarich were the soil formations exposed by the construction. When he and his students took a closer look, they realized they’d discovered nothing less that a previously unknown deposit of ancient soil, or “geosil.”
Last November, Tandarich was notified by Dr. Leon Follmer of the Illinois State Geological Survey that he and his students would be accorded the opportunity to officially name a new “soil stratagraphic unit.” They wrote a scientific paper in which they named their discovery “the Rosary Geosil,” in honor of the university’s former name (Rosary College).
Now Tandarich says he may have stumbled on much more. When he studied the exposed soil layers, he noticed an oddity.
“The top one was Equality, the middle was Henry, and the bottom was Wadsworth,” he recalled, naming the three major soil formations that comprise the earth around the Chicago area-only they were out of the usually observed order.
“Usually the Henry formation is on the surface,” he said. “The Henry, the sand, is usually found on the surface.” Instead, the sand layer was covered by Equality, which was supposedly formed earlier.
It is widely accepted that floods, caused by the melting of the massive Laurentide Ice Sheet moving down from the Arctic, left most of what’s now the Chicago area under an equally massive “Lake Chicago,” starting around 17,000 years ago and lasting until 12,500 years ago. That period-the Glenwood Phase-created the Henry Formation, a thick layer of sandy soil near the surface of today’s modern soil cover.
According to the consensus model, the Glenwood Phase was continuous. Not so, Tandarich suggests. “This does not fit the accepted paradigm,” he said. “This is covered by the Equality formation from Lake Chicago,” which was laid down before the Henry formation was created.
The new geosil he’d found, Tandarich said, had all the characteristics of “cold climate soil.”
“When it was first laid down (about 17,500 years ago), it was not covered by ice or water,” he explained. “And soil developed in the deposit.” Rain, snow, microbes and other weathering factors worked on the deposit over centuries, and a geologically distinctive soil was gradually created, one formed only in very cold climates-climates exposed to the air, not submerged under a lake.
If Tandarich’s hypothesis is true, the Chicago area’s soggy Glenwood period took place in two parts-Glenwood stage one and Glenwood stage two. In between, the Rosary Geosil was formed. “The area was dry for 2,000 years,” said Tandarich. “This may lead to a new review in thinking regarding geologic history.”
While there’s no question regarding the environment in which the Rosary Geosil soil formed, there is a question about the exact age of the soil. Luckily for Tandarich, one of his students, Daniel Lynch, found the intact remnants of ancient bugs in the soil. Such organic material can be accurately dated by the scientific Carbon 14 dating process. He hopes to get the test results back by early spring.
“It was exciting to find something that had never been described before,” Tandarich said.
The excitement could increase if it leads to a revision of local geological history.